Self-heating soldering-iron.



R. W. MARVELL.

SELF HEATING SOLDERING IRON.

APPLICATION FILED JAN. 24, 1912.

1,080,644. Patented Dee.9,1913.

COLUMBIA PLANOURAPII c0..WAsHlNu'roN. l c,

entran strains rarnnr euries.

ROY W. MARVELL, OF BALTIMORE, MARYLAND, ASSIGNOR, BY MESNE ASSIGNMENTS, TO LYON, CONKLIN & COMPANY, A CORPORATION OF DELAWARE.

SELF-HEATING SOLDERING-IRON.

Specification of Letters Patent.

' Vatented I)ee.9,1913.

Application filed January 24, 1912. Serial No. 673,269.

To all whom t may concern:

Be it known that I, ROY W. h/Llnvnnn, a citizen of the United States, and a resident of Baltimore, Maryland, have invented a new and useful Self-Heating Solt'lering- Iren, ef which the 'tollowing` is a specification. l

Among` the objects of my invention are te provide in connection with a solderingl tip, a reservoir for liquid fuel, such as gaselene, means for putting; the fuel under pressure, a burner and mixing' tube ef nevel censtructien by which a very het flame is applied te the base of the tip with a small rate of fuel consumption, and improved means for feeding and regulating' the flew of fuel to the mixing` tube.

Another object is te provide the device with a novel form of handle and te locate this handle se that the tool will be properly balanced in the hand of the user.

In addition to carrying out the foregoing' objects, the invention consists in certain nevel forms and combinations of parts, as will appear.

The accompanying drawing' shows one exemplifying;` embodiment of the invention.

Fig-ure l is a side view of a tool embodying the invention. Fig'. 2 shows the reservoir, handle and part of the feed tube in longitudinal section. Fie. 3 is a longitudinal section of the combustion chamber, mixing tube, needle valve and adjacent end of the feed tube. Fig. 4 is an enlarged section of the needle valve. Fig. 5 is an enlarged len- ,eitudinal section of the check valve, and Fie'. 6 is a crossseetion en the line G-G of Fig. 2.

Reference character l designates, in gjeneral, a reservoir, the shape of which can, of course, be greatly varied. One end of the feed tube 2 is screwed inte the reservoir by means ef a nut- 3. At the other end, the feed tube is screwed inte a body l which contains the needle valve. The mixing tube 5 is screwed upon a projection 7 formed on the body 4L. At the end of the mixing tube is the combustion chamber 8, and `into the end of this is screwed the soldering tip er peint 9, the shape of which may be greatly varied to suit particular necessities. lVithin the valve body l, adjacent te the end of the feed pipe 2, is provided a small gasolene chamber 10.' This is usually most conveniently formed by the peint of the drill which bores `the hole for the reception of the feed tube. From this chamber l() a small conduit l1 leads to a valve chamber .l2 ef small size surrounding the stem 13 of the needle valve. This stem adjustably engages the body 4; by means of a scre\vthread le and is previded with a suitable packing and packing' nut 'l5 te make the stem liquid and vapor tight where it emerges from the valve body. On the outer end of the stem is a head 1C which may be linurled er provided with holes '17, as shown, for the adjustment of the valve. The valve scat 20 has a straight conical bere, as more clearly shown in Fig. 4l. The valve, in the preferred construction as shown, comprises an inner conical. portion 2l designed to exactly fit the valve seat and an outer more steeply tapered conical portion This outer tapered portion leaves a l:gradually outwardly expanding' space Q3 between the valve and its seat communicating with the mixing' tube As shown in Fig'. 3, the inner form of the pol'tion 30 of the mining; tube adjacent te the valve is cylindrical. llut as the tube appreaches the combustion chamber, the bere of the tube is inwardly tapered as at 31 te a restricted throat or nozzle 32 immediatelyT adjacent to the combustion chamber. The cross-sectional shape of the interior of the ('-eml'iustion chamber is preferably circular, the head 35 or end of the ehaml'ier adjacent to the mixing' tube usually being' larger than the other end and tapering' to meet the base of the solderingl point, as shown. The eut side of the conll'iustion chamber is mest conveniently formed into opposite llattened faces 3G so that a wrench or vise may be easily applied to the combustion chamber when it is desired te remove the point f).

Air is supplied to the mixing` tube through holes 40, desirably four in number, a1"an9;ed as shown at the base of the mixing tube immediately adjacent to the peint of entry of the needle valve. lreducts of eombua tion are discharged from the combustion chamber through holes 45, and the number and arrangement of these holes is important. lt is desirable in most cases to have the size of the holes l5 bear approximately the relation to the size of the combustion chamber shown in lthe drawing'` and when the holes are et this size it is desirable to have them arranged substantially as shown in the drawings, that is with about four holes on idly away from the base of the tip. This arrangement provides just the right flue space for the discharge of burned gas and at the same time concentrates most of the hot flame on the base of the tip where it serves most effectively to heat the same.

The feed tube 2 is curved at the points 50, 51, to bring the combustion chamber and mixing tube in line with the reservoir, also vfor another purpose as will appear. A wick 53 extends from the top end of the reservoir through the feed tube 2 to a point 54 (Figs. 2 and 3) within the feed tube near the valve body 4.' Between the end of the wick 53 and fuel chamber l() is an asbestos packing 55, which is tight-ly packed into the end of the tube. This asbestos takes up the duty of a capillary feed for the fuel at the point where the wick stops and prevents burning out of the capillary feeding means, since the asbestos, of course, is notaffected by heat to which the end of the feed tube 2 adjacent to the valve body 4 is subjected. The

double tapered valve 20, 21, affords meansv for very closely regulating the fuel supply. The construction of fuel passages and valve in combination with the described arrangement of mixing tube and combustion chamber produces a very vigorous draft and an intensely hot blue flame, the flame being confined entirely to the combustion chamber and concentrated mainly against the base of the point as it issues through the holes adj acentthereto. The point may be quickly heated to a cherry red and even melted in a very short time, unless the fuel feed is greatly restricted, and by proper adjustment the iron may, therefore, be used outdoors on the coldest days with perfect success.

Air pressure is supplied to and maintained in the reservoir by means of a novel check-valve, generally designated by the character V, F ig. 2, and shown in detail in Fig. 5. A nut 60 is screwed into the reservoir and is provided with a suitable packing 6l. An extension 62 is interiorly threaded to receive a pump connection and exteriorly threaded to receive a cap 63. At the inner end of the nut is an extended nipple Get. A long thimble 65 is screwed onto the base of nipple 64 and accommodates a check-valve 66. A suitable packing in the end of this valve engages the end of the nipple. The valve stem 67 extends through a hole in the end of the thimble, which forms a guide for the movement of the valve. A spring 68 compressed between the end of the thimble and the valve urges the latter against its seat. A perforation 69 in the thimble permits air to pass from the pump past the check-valve to the reservoir, and when suflicient air has been forced into the reservoir, the check-valve retains this pressure in an obvious manner.

1n ordinary soldering irons, the handle is at one end of a rod and the soldering point at the other end. This heavy point so far removed from the handle puts a severe strain on the hand and wrist of the user. ln my self-heating iron I provide a handle H centrally located, so that the weight of the tool is evenly balanced and so that the user will not be fatigued even when the tool is used for a long time continuously. The

i handle comprises two blocks 80 of wood or other suitable material on the center line of y the tool and each one is channeled out to lit the curved feed tube 2. At the end adjacent the reservoir, the blocks are also hollowed out to closely iit the nut 3, so that any tendency of the handle to rotate on the tube is prevented. The two blocks are clamped together by screws 8l. Usually a sheathing or sleeve 82, conveniently of asbestos, is placed between the handle and the tube to insulate one from the ot-her.

I claim:

l. 1n a soldering iron, the combination with a valve body and valve, of a mixing tube provided with air ports immediately adjacent the valve, a combustion chamber at the opposite end of said tube,-the inner diameter of the tube being restricted at the point of entry to said combustion chamber, a soldering tip at the outer end of said chamber, the chamber being provided with a multiplicity of iiue holes, the combined area of said holes decreasing from the base of said tip toward the opposite end of the chamber.

2. In a soldering iron, the combination of a mixing tube, a valve body at one end thereof, an enlarged inclosed combustion chamber at the other end of said tube, a solid soldering point screwed in the outer' end of said chamber, said point having a solid substantially flat base exposed to flame in said chamber, a valve in the valve body for supplying fuel to the base of the mixing tube, air-supply openings in the tube adjacent to t-he valve, the mixing tube being unapertured from said openings to the combustion chamber, the mixing tube being also provided. with a restricted throat or nozzle at the point of entry into the combustion chamber, the combustion chamber being provided on all sides with a multiplicity of flue holes, the combined area of said holes decreasing from the base of the soldering point toward the other end of the chamber.

3. 1n a soldering iron, the combination of u reservoir, u fuel conduit, a valve body secured at one end of the fuel conduit, a mixing tube secured to the vulve body, a vulve within the valve body, said valve discharging into one end of the mixing tube, the mixing tube being provided with air supply openings adjacent to the valve, a combustion chamber at the end of the rniX- ing tube, the mixing tube being provided with a constricteel nozzle at the point of entry into the combustion chamber, a soldering point secured in the outer end of the combustion chamber, the combustion chamber being provided with u multiplicity of flue holes, said holes being provided closer together und in greater number adjacent to the base of the soldering point, und decreasing in number und being spaced farther apart toward the opposite end of the combustion chamber.

ROY WV. MARVELL. Vitnesscs D. M. SMITH, M. A. Woon.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

